A multi-spectral scanning fiber endoscope (SFE) will be developed to image the panel of fluorescent-labeled peptides developed in Project 2 that have specific binding activity to amplified and/or over expressed gene targets identified in Project 1. Image processing algorithms will be developed to stitch together individual images to form a panorama of the esophageal mucosal surface, and red-flag idenfificafion of highgrade dysplasia and early adenocarcinoma will be performed in Core B to assist the physician by guiding biopsy. The performance of this integrated imaging strategy will be validated in Core C. This instrument will pass through the working channel of a medical endoscope in Phase 1 clinical studies of the individual pepfides assigned to three fiuorescent-labels in Project 2. The expected establishment of safety will prepare this system for a future multi-center clinical validation study.